Diffraction studies of cubic phase stability in undoped zirconia thin films

Pure stoichiometric ZrO2 films were deposited on amorphous silica substrate s by electron beam evaporation of Zr in the presence of an electron cyclotr on resonance oxygen plasma. Grain size, strain, and texture were analyzed b y x-ray diffraction and reflection high-energy electron diffraction. Films grown at room temperature are polycrystalline and exist in the cubic phase. Growth at elevated temperatures produces coexisting cubic and monoclinic p hases and shows a maximum critical grain size of similar to 10 nm for stabi lization of the cubic phase. Pole figure analysis indicates a preferred cub ic [200] fiber axis for room-temperature growth and dual monoclinic {111} a nd {11 (1) over bar} in-plane textures for films grown at 400 degrees C. Po stdeposition annealing experiments confirm the existence of a critical grai n size and suggest mechanisms for grain growth.